1. Field of the Invention
This invention relates to a truth value converter used in a truth-valued-flow processing unit for processing such information as fuzzy information, 2-valued information and multivalued information.
As will be set forth in this specification, a truth value refers to a concept which includes the truth values in 2-valued and multivalued logic, as well as the grades of membership functions in fuzzy theory.
2. Description of the Prior Art
Systems have been developed for performing fuzzy inference in accordance with a modus ponens inference format referred to using such names as fuzzy computers, fuzzy controllers, fuzzy inference units, fuzzy operation units, fuzzy processing units and the like. These systems are the object of much attention. Fuzzy inference units generally are of two types, namely analog and digital. The analog-type fuzzy inference unit has a high inference speed but involves some difficulties in terms of achieving interfacing with a digital computer. On the other hand, the digital-type inference unit has a slightly lower inference speed than that of the analog type but is easy to connect to a digital computer.
Both the analog and digital-type units have a plurality (and in some cases, a large number) of rules referred to as "If, then" rules, which are accompanied by membership functions, set for them, and they perform predetermined inference processing in accordance with these rules. Since the inferential results of each rule are given by the form of the membership function, it is required ultimately to combine inferential results for each and every rule and, in some cases, to defuzzify the results. In general, since a membership function is expressed as a distribution of signals, a large number of lines are required to transmit the function. The result is a complicated circuit arrangement.